Abstract:

The aim of the study was to evaluate the influence of low-temperature heat treatment on the physical and technological properties of pork. The Longissimus thoracis muscles from four pigs were used to determine the quality indicators of pork at 24 hours after slaughtering. Meat samples were cooked at constant 120 °C in a cooking bag until the internal temperatures of 62, 67, 72, 77 and 82 °C. Raw meat was the darkest and differed considerably (P < 0.05) from the heat-treated meat. The colour values of the heat-treated meat differed slightly among internal temperature phases. The ultimate pH value of raw meat also differed significantly (P < 0.05) from that of cooked meat. The pH value of cooked meat varied only within the range of 0.05 units. The electrical conductivity of muscle decreased gradually as the temperature increased. In case of heat-treated meat, the cooking loss increased considerably (from 18.88% to 31.73%) along with the increase in the internal temperature. The Warner-Bratzler shear force value was the highest (38.50 N) in the meat cooked until 77 °C, and the lowest (28.51 N) in that cooked until 67 °C. Strong negative correlation (P < 0.001) between electrical conductivity and cooking loss was observed during the heating procedure. Heat treatment can significantly decrease the electrical conductivity and increase the cooking loss of meat. Meat was the toughest when the internal temperature was 77 °C. However, the best rheological properties were observed in the meat cooked until the internal temperature of 72 °C.